Prior support structures for use with internal combustion engines having cylinder liners have been directed generally to supporting lightweight engine cylinder blocks and/or liners against high combustion gas loads. See for example U.S. Pat. Nos. 4,757,790 and 4,858,462 to Ushio et al.
In addition to supporting the block and liner against high combustion gas loads, internal combustion engines must also support the block and/or liner against thermal and mechanical loads. For example, in an internal combustion engine including removable flanged cylinder liners top or mid-supported by the cylinder block, manufacturing tolerances and thermal distortion can cause high localized contact stresses in the abutment of the cylinder liner flange with the cylinder block. For flanged cylinder liners supported by the top surface or deck of the cylinder block, cracking of the top deck adjacent to the cylinder bore occurs. Left unchecked, crack propagation between adjacent cylinder bores can result in loss of compression and reduced engine performance.
Further, overhaul of the engine is made more difficult. For small cracks in the top deck of the cylinder block observed during overhaul, the deck is typically counterbored around the cylinder bore to a depth which eliminates the cracks, and a cylindrical ring is inserted between the cylinder liner flange and counterbore to reestablish the cylinder liner flange height. However, the cylindrical ring, like the cylinder block, is still subject to high localized stresses and cracking due to manufacturing tolerances and thermal distortions. Further, additional shims are typically required to reestablish the proper cylinder liner flange height. If the cracks have propagated beyond the permissible repair range, the cylinder block must be replaced.
Therefore, a need exists for an improved abutment of the cylinder liner to the cylinder block which reduces cracking of the cylinder block. Preferably, such an abutment should be easily repairable without affecting engine performance. Ideally, such an abutment should be retrofittable to existing engines.